It is known to exhaust gases from rooms containing toilets by way of ceiling or wall mounted exhaust fans. However, a disadvantage of exhaust systems of this type is that unpleasant odours must be drawn from the toilet pan and through the room in order to reach the exhaust fan. Accordingly, subsequent users of the toilet often still encounter unpleasant odours. This situation is exacerbated when the toilet is located in a confined space and/or located adjacent habitable or food preparation areas.
Ventilation devices that withdraw gases directly from domestic toilet pans are also known. Such devices generally include an inlet in gas communication with the interior of the toilet pan that is connected to a suction device. The suction device is in turn connected to an outlet positioned remotely from the room that contains the toilet. Removing odours directly from the toilet pan substantially lowers the chance of a subsequent user of the toilet, or anyone near the room containing the toilet, from encountering unpleasant odours.
The extracted unpleasant odours are commonly exhausted to the exterior of the building that houses the toilet via ducting. The ducting is usually installed inside a wall (either chased into masonry or positioned within stud wall partitions) for concealment. However, this makes such installations difficult, particularly running the ducting to a suitable exterior discharge point, and expensive and only suitable for use in bathrooms that are either under construction or refurbishment. It is also often difficult to obtain an adequate power supply given many known systems use a fan driven by a 240 Volt AC motor.
To alleviate some of these problems, it is also known to direct the unpleasant odours directly into the sewer, at a location downstream of the toilet water seal (ie. water trap). However, to meet the plumbing codes and regulations in many jurisdictions, such a system must include an approved one-way valve between the suction device and the outlet sewer.